// Add implementation("com.android.installreferrer:installreferrer:2.2") to your app module.
// No SAIRO secret belongs in the app. Forward pending values to YOUR authenticated backend.
package com.sairo.referral

import android.content.Context
import android.net.Uri
import com.android.installreferrer.api.InstallReferrerClient
import com.android.installreferrer.api.InstallReferrerStateListener

class SairoReferral(context: Context) {
    private val context = context.applicationContext
    private val prefs = this.context.getSharedPreferences("sairo_referral", Context.MODE_PRIVATE)
    fun pending(): String? = prefs.getString("pending", null)
    fun capture(url: Uri): Boolean {
        val ref = url.getQueryParameter("ref") ?: url.getQueryParameter("sairo_ref")
        val code = url.getQueryParameter("sairo_code")
        val value = ref?.takeIf { it.length <= 2000 && Regex("[A-Za-z0-9_-]+\\.[a-f0-9]{64}").matches(it) }
            ?: code?.replace("-", "")?.trim()?.uppercase()?.takeIf { Regex("[A-F0-9]{20}").matches(it) }
            ?: return false
        // Keep first pending referral. Your backend must not overwrite committed attribution.
        if (pending() == null) prefs.edit().putString("pending", value).apply()
        return true
    }
    fun enterCode(code: String): Boolean = capture(Uri.Builder().scheme("https").authority("local.invalid").appendQueryParameter("sairo_code", code).build())
    // Clear only after your backend commits attribution, not before a network request.
    fun acknowledge() { prefs.edit().remove("pending").apply() }
    // Invoke once at first launch; transient failures can be retried on a later launch.
    fun readInstallReferrer(done: (Boolean) -> Unit) {
        if (prefs.getBoolean("install_read", false)) { done(pending() != null); return }
        val client = InstallReferrerClient.newBuilder(context).build()
        var finished = false
        fun finish(ok: Boolean) { if (!finished) { finished = true; client.endConnection(); done(ok) } }
        try {
            client.startConnection(object : InstallReferrerStateListener {
                override fun onInstallReferrerSetupFinished(responseCode: Int) {
                    if (responseCode != InstallReferrerClient.InstallReferrerResponse.OK) { finish(false); return }
                    try {
                        val value = client.installReferrer.installReferrer
                        val captured = capture(Uri.parse("https://local.invalid/?" + value))
                        prefs.edit().putBoolean("install_read", true).apply()
                        finish(captured)
                    } catch (_: Exception) { finish(false) }
                }
                override fun onInstallReferrerServiceDisconnected() { finish(false) }
            })
        } catch (_: Exception) { finish(false) }
    }
}